1. Technical Field
The present disclosure relates to an image processing apparatus that can obtain surface unevenness information or surface topography images.
2. Description of the Related Art
An endoscope captures an image of an organism's organ by irradiating the wall surface of the organ, which is covered with a mucosa, with illuminating light. In the field of such endoscopes, not only changing colors of the surface but also the texture of minute unevenness on the surface need to be observed and confirmed. However, in order to avoid casting shadows on the object, an endoscope usually sets the angle formed between the optical axis of the illuminating light and that of image capturing light to be approximately zero degrees, and therefore, it is difficult for the endoscope to capture such a surface unevenness structure (micro-geometry or surface topography) with shadows. To overcome such a problem, someone has proposed a technique for recognizing the surface unevenness by reference to information about the color shade of the given image by slightly modifying the image processing process for an existent color luminance based endoscope image capturing system. Meanwhile, a polarization endoscope that uses a polarized light source and polarization image capturing in combination has also been proposed.
The former technique is disclosed in Japanese Patent Publication No. 3869698, for example.
Meanwhile, the latter technique is disclosed in Japanese Laid-Open Patent Publication No. 2009-246770 and Japanese Laid-Open Patent Publication No. 2010-104424, for example.